Japanese Patent Application Laid-open No. H05-345156 discloses a conventional electrostatically atomizing device for generating charged minute particles of nanometer size (nanometer-size mist). In the device, a high voltage is applied across an emitter electrode, supplied with water, and an opposed electrode, to induce Rayleigh breakup of the water held on the emitter electrode, thereby atomizing the water. Such charged minute water particles, long-lived and containing active species (radicals), diffuse throughout an environment space, adhering to and/or penetrating into objects present in the space, so that these objects can be effectively sterilized and deodorized as a result.
The mist of charged minute particles comprises active species (radicals), and hence the mist can potentially elicit a sterilizing and deodorizing effect on germs and harmful substances that are present in the environment space. Sterilization by the active species (radicals) contained in the mist of charged minute particles is the result of germs and harmful substances being engulfed by the charged minute water particles W during the flight of the mist of charged minute particles or when the mist of charged minute particles adheres to target objects. In consequence, the germ and harmful substance elimination effect is observed only during the flight or adhesion of the mist of charged minute particles. That is, the mist is effective against germs and harmful substances present in the space only at such times. This is problematic in that such elimination effect cannot be expected to work against new germs and harmful substances that develop on, or adhere to, objects in the space, once a certain time has elapsed since adhesion of the mist of charged minute particles onto the target objects. Also, there are cases in which the sterilizing effect of the active species contained in the mist of charged minute particles is insufficient for the environment in which the mist is used, where a greater sterilizing effect is thus required.